The shield in the left has the semme hearts where as the shield on the right is the version without the semme of hearts. You can notice the difference in the top right quarter.

George III Shilling 1787 With Semme Of Hearts

Courtesy of Rob Pearcewww.rpcoins.co.uk

Courtesy of Rob Pearcewww.rpcoins.co.uk

The 1763 shilling was distributed by the Earl of Northumberland (Sir Hugh Percy) upon appointment as Lord-Lieutenant of Ireland. He was one of George III's confidential advisers.

There are four different obverses and five different reverses issued for the shillings of the George III reign.

The 1787 shilling was by Luis Pingo. There are two different reverses for the 1787 shilling. One with a semme of hearts and one without. There isn't any difference of value or rarity between them.

The 1798 shilling was struck from silver supplied by banks they are called the Dorrien and Magens shillings. These coins were soon afterwards voted to be illegal and most were melted down so they are extremely rare.

The 1816-1820 shilling obverse were by Benedetto Pistrucci. The reverses were designed by Thomas Wyon.